Change zecwallet lightwalletd server

[oxarbitrage]

Describe the bug
When i try to change the lightwalltd server to for example the community server option in France or my own custom server the lightwalletd will not change it even after restart.

To Reproduce
Steps to reproduce the behavior:

1. Go to wallet -> server info
2. Click on switch lightwalletd server
3. Select ZcashFR (Community) - https://lightd-main.zcashfr.io:443
4. Restart
5. Go to wallet -> server info

The server did not changed.

Expected behavior
Server should change or error if server is down, out of sync, etc.

Is there a way to force the selected server to be used without fallback ?

Desktop (please complete the following information):

• OS: linux
• Browser .deb package
• Version Zecwallet Lite v1.7.8

Additional context
ZcashFoundation/zebra#3655

[conradoplg]

I've investigated this a bit but I don't know the best way to fix it.

It seems the logic to configure the lightwalletd server was commented out in #109

I tried restoring it but ran into issues with electron-store ("fs.existsSync is not a function")

[softminus]

This seems like a duplicate of #67